The present invention is directed to a novel catalytic process for converting methanol and dimethyl ether to hydrocarbons.
The conversion of dimethyl ether in the presence of a predominantly isobutane diluent to a mixture of normally liquid hydrocarbons predominantly of the isoparaffinic and aromatic types using synthetic alumina, synthetic aluminasilica, or acid-leached alumina catalysts is known (see U.S. Pat. No. 2,456,584). It is also known that tertiary monoolefins can be prepared from the decomposition of tertiary ethers in the presence of a catalyst comprising a carrier material, e.g., alumina, having a specific surface area of at least 25 m.sup.2 /g combined with a weakly acidic component, e.g., a weakly acidic aluminum sulfate (see British Pat. No. 1,173,128).
Conversion of methanol and dimethyl ether by contact with a catalyst comprising a crystalline alumina silicate zeolite is described in U.S. Pat. No. 3,911,041.
Applicants have discovered that methanol and dimethyl ether can be converted to higher hydrocarbons at elevated temperatures by contacting either or both of them with a catalyst comprising aluminum sulfate on a support selected from alumina, zirconia, and silica.